PL165117B1 - Method of recovery of useful minerals by means of reverse foam flotation - Google Patents

Abstract

1. A METHOD OF RECOVERING USEFUL MINERALS BY REVERSE FOAM FLOTATION, CONSISTING OF SUBJECTING AN ORE CONTAINING SILICA OR SILICEUS FRUIT ROCK AND IS IN THE FORM OF AN WATER SUSPENSION TO FOAM FLOTATION, CHARACTERIZED IN THAT THE FLOTATION IS CARRIED OUT IN THE PRESENCE OF AN AMINE COLLECTOR AND AT LEAST ONE ALKANOLAMINE UNDER CONDITIONS IN WHICH SILICA OR SILICEUS FRUIT ROCK ARE FLOTTED, AND THE USEFUL MINERALS REMAIN IN THE WASTE. PL PL

Description

The present invention relates to a method of recovering minerals useful by reverse flotation in which silica or siliceous gangue is flotated.

Flotation is a method of treating a mixture of finely divided mineral solids, e.g. powdered ore, which is suspended in a liquid, which separates some of the solids from other finely divided mineral solids, e.g. silica, siliceous gangue, clays and other similar materials present in the ore by introducing a gas (or creating a gas in place) into the liquid to form a foamed mass that contains some of the solids on the surface of the liquid while leaving other solid components of the ore in suspension (earthened). Flotation is based on the phenomenon that introducing a gas into a slurry of particles of various solids in a liquid causes the gas to adhere to some, but not all, of the solids in the slurry, making the particles attached to gas bubbles lighter than the liquid. Accordingly, these particles rise to the surface of the liquid, forming a foam.

The froth flotation minerals and associated gangue usually do not have sufficient flotation or hydrophilicity to perform a suitable separation. Therefore, in froth flotation, various chemicals are often used to obtain or increase the necessary properties; enabling separation. Collectors are used to enhance the htdroSlbleośó and hence the flotation ability of various useful minerals. The collectors must have the ability to: attach to the desired types of minerals with relative exclusion of other minerals present; maintaining this connection in the face of turbulence and shear phenomena associated with planned flotation, and to give the desired types of minerals sufficient hydration to obtain the required degree of separation.

In addition to the collectors, many other chemicals are used. Examples of types of additional reagents are agitation, aepressure, pH regulators such as quicklime and soda, dispersants, and various promoters and activators. Depressions are used to increase or enhance the phololarity of various types of minerals and thus inhibit their flotation. Frothers

165 117 are reagents added to the flotation system to facilitate the formation of semi-permanent foam. Unlike depressants and collectors, frothers do not need to attach to or adsorb to mineral particles. Promoters and activators enhance or enhance the effectiveness of other reagents such as collectors and depressants.

Foam flotation has been widely used in mining since at least the early twentieth century. In a typical, or simple, flotation, the useful or desired mineral is flotated from the waste rock material that remains in the waste. In another type of flotation called reverse flotation, an undesirable mineral such as silica or siliceous gangue is flotated with useful minerals that remain in the waste.

A large variety of compounds are known to be useful as collectors, frothers and other reagents for the purposes of froth flotation. For example, in reverse flotation, where silica or siliceous gangue is flotated from useful minerals, amines such as simple primary and secondary amines, primary etheramines and ether diamines, tallow amines, and tall oil-amine fatty acid condensates are generally considered to be useful collectors. Reagents useful as frothers include lower molecular weight alcohols such as methyl isobutyl carbinol and glycol ethers. The specific additives used in a given flotation are selected according to the type of ore, the conditions under which the flotation will occur, the mineral to be recovered and other additives that may be used with them.

It is known that the effectiveness of these known reagents varies greatly depending on the type of ore or ores to be flotated, and also on the flotation conditions. One of the known problems is that the amine collectors used to flotate silica are often not as selective to silica as desired and the useful mineral also flotates with the silica resulting in reduced yields of the desired minerals in the waste.

Thus, there remains a need for more efficient methods of removing silica or siliceous gangue from minerals useful for reverse flotation.

The present invention provides a process for recovering minerals useful by reverse froth flotation that involves subjecting a particular ore that contains silica or silica gangue and is in aqueous suspension to foam flotation in the presence of an amine collector and at least one alkanolamine under silica flotation conditions. or siliceous gangue and useful minerals remain in the waste. Moreover, frothers and other known flotation reagents are used in the froth flotation process of the invention.

The flotation method of the invention is useful in the recovery of various minerals, including oxide minerals, by reverse froth flotation. Unexpectedly, it turned out that the use of small amounts of alkanolamine together with amine collectors increases the operation of the amine collector.

The reverse flotation method of the invention is useful in recovering minerals useful from a variety of ores containing silica or silica gangue. The term ore denotes the mineral as it is extracted from the earth and includes material containing the mineral in admixture with gangue including siliceous gangue. Gaste is those materials that are of little or no value and which must be separated from the useful minerals.

Examples of silica-containing oxide ores that can be treated by the process of the invention preferably include iron oxides, nickel oxides, phosphorus oxides, copper oxides, and titanium oxides. The treatment of iron-containing and phosphorus-containing ores is particularly advantageous. Other types of oxygen-containing minerals having silica gangue that can be treated by the process of the invention include carbonates such as alcite or dolomite and hydroxides such as bauxite.

Various silica-containing sulphide ores may also be treated using the process of the invention. Examples of sulphide ores which can be flotated by the process of the invention include those containing chalcopyrite, chalcosine, galena, pyrite, sphalerite, and pentlandite.

165 117

Those skilled in the art recognize that various silica-containing ores can be reverse flotated in which the siliceous gangue is flotated with the desired useful minerals. , valerite, calcite, talc, kaolin, apatite, dolomite, bauxite, spinel, corundum, laterite, azurite, rutile, magnetite, columbite, ilmenite, smitsonite, anglesite, shellite, chromite, cerusite, pyrolusite, malachite, chrysocolla, zincite, massikote , bixbyite, anatase, brukite, tungstite, uraninite, gummite, brucite, manganite, psylomelan, getite, limonite, chrysoberyl, microlyte, tantalite and samarskite. It will be appreciated by those skilled in the art that the reverse froth flotation method of the present invention will be useful for treating additional ores including oxide ores where the oxide is defined to include carbonates, hydroxides, sulfates, and silicates, as well as oxides and sulfide ores.

The reverse flotation method of the invention can be used not only for the flotation of naturally occurring ores, but also for the flotation of oxides and sulfides from non-natural sources. For example, wastes from various processes such as heavy media separation, magnetic separation, metalworking, and petroleum refining often contain oxides and / or sulfides with silica or silica gangue that can be recovered using the reverse flotation method of the invention.

Collectors which are suitable for flotation of silica in the process of the invention are known in the art and include amine collectors containing at least 12 carbon atoms. Examples of such collectors are primary amines, secondary amines, primary etheramines and ether diamines, tallow amines and tall oil fatty acid condensates with an amine. Examples of such collectors include 3-nonyloxypropanamine; N- (3-tridecyloxylpropyl) -1,3-diaminopropane; a condensate of diethylenetetramine and tall oil fatty acid; tallow amine with 16 to 18 carbon atoms, decylamine, dihexylamine and the condensate of excess fatty acids with diethanolamine.

In the present invention, alkanolamines are used to increase the flotation of silica by reverse flotation. Preferably, the alkanolamines used in the practice of the invention should be lower alkanolamines containing 1 to 6 carbon atoms. In a preferred embodiment, the alkanolamines are represented by the formula (R) _x NH (3- _x ) where x is from 1 to 3, and each R is independently an alkanol with 1 to 6 carbon atoms. In an even more preferred embodiment, the alkanolamine is ethanolamine, diethanolamine, triethanolamine, propanolamine, isopropanolamine, butanolamine, isobutanolamine or mixtures thereof.

Alkanolamines useful in the practice of the invention are commercially available. As is known, the commercially available alkanolamines have various degrees of purity. For example, commercially available diethanolamine may contain varying amounts of ethanolamine and / or triethanolamine. Such alkanolamines are suitable for the practice of the present invention.

The alkanolamines can be added directly to the flotation cell or in the grinding stage. The preferred addition time will vary with the type of ore flotated, other reagents, and the treatment system used. Preferably, it is not subjected to premixing, ie prior to introducing alkanolamines with the amine collector into the flotation system. The alkanolamines and collector are added to the flotation system separately. They are also preferably added before adding the collector. For example, alkanolamines can be introduced in a grinding step.

The amine collector can be used at any concentration that will flotate a sufficient amount of silica or siliceous gangue to provide the desired yield of the desired minerals useful in flotation tailings. In particular, the concentration value used depends on the type of mineral to be treated, the quality grade of the ore subjected to the froth flotation process, and the desired quality of the mineral that is recovered. Additional factors to consider in determining the dosage level include the size of the treated ore specific surface area. It is known to those skilled in the art that the smaller the particle size, the greater the amount of collector is needed to achieve the desired yield and useful mineral content in the recovered mineral.

Preferably, the concentration of the collector is at least 0.001 kg / ton of ore, more preferably at least 0.005 kg / ton. It is also preferred that the total collector concentration is not more than 5.0 kg / tonne, and more preferably not more than 2.5 kg / tonne. More preferably, the collector concentration is between 0.005 kg / ton and 0.100 kg / ton. Typically, it is preferable to start with low concentration ranges and gradually increase the concentration to the best effect.

The concentration of alkanolamines according to the invention is at least sufficient to show a reduction in the amount of useful mineral inadvertently flotated from silica or silicon in gangue. This concentration is preferably at least 0.001 kg / ton of dry solids and not more than 1.5 kg / ton. More preferably the concentration is between 0.01 kg / tonne and 0.10 kg / tonne.

When recovering certain minerals, it has been found advantageous to add the collector to the flotation system gradually or in stages. This should be understood as, that a part of the total collector dose is added, the foam concentrate is collected, another portion of the collector is added, and the schedule concentrate is collected again. This stepwise addition may be repeated several times to obtain an optimal yield and an appropriate useful mineral content in the recovered mineral. The number of steps in which the collector is added is only limited by practical and economic reasons. Preferably, no more than about 6 steps are used.

In addition to the amine collectors and alkanolamines, other conventional additives, including other collectors, may be used in the flotation process of the present invention. Examples of such additives include depressants and dispersants. In addition to the additives mentioned, there may be and preferably frothers are used. Frothers are well known in the art. They are mentioned herein for the purposes of the invention. Non-limiting examples of useful frothers include alcohols of 5 to 8 carbon atoms, pine oils, cresols, alkyl esters of polypropylene glycols wherein the alkyl comprises 1 to 6 carbon atoms, propylene glycol dihydroxylates, glycol fatty acid esters, soaps, alkylarylsulfonates, and mixtures thereof .

The pH can be adjusted in flotation systems by various methods known to those skilled in the art. Quicklime is a common reagent used to adjust pH. However, it is also possible to use reagents such as sulfuric acid, hydrochloric acid, potassium hydroxide, sodium hydroxide, ammonium hydroxide, sodium carbonate and the like in the practice of the invention.

The following examples are presented for the purpose of Illustration of the invention. They should in no way be interpreted as limiting the invention. All parts and percentages are by weight unless otherwise indicated.

Example I: Flotation of Oxide Iron Ore. A series of 600 gram samples of Michigan oxide iron ore was prepared. The ore was essentially magnetite with minor amounts of hematite, martite, and goethite. The processing raw material from which the samples were made was ground such that up to 82% of the grains were smaller than 75 µm and contained 11.3% silica and 46.7% iron. Each 600 gram sample was individually milled with 400 grams of deionized water in a rod mill at approximately 60 rpm for 2 minutes. The obtained pulp was transferred to the 3000 ml chamber of the Agltair flotation plant equipped with an automated blade removal system. Water was added to completely fill the chamber volume. The pH of the slurry was left unchanged, which in the natural ore slurry was 6.5 before the addition of the alkanolamines according to the invention. The alkanolamine, if used, was added to the suspension and the suspension was conditioned for one minute. A collector as shown in Table 1 was then added and conditioned for an additional 1 minute. Thereafter, polyglycol ether was introduced as a oxygenator in an amount equivalent to 5 g / tonne of dry ore and conditioned for a further 1 minute.

The contents of the flotation cell were mixed at a speed of 900 revolutions / minute by introducing air in the amount of 9.0 liters per minute. Removal of the silica concentrate took place within 10 minutes. Samples of the silica concentrate and iron containing waste were dried, weighed and pulverized for analysis. Then they were dissolved in acid and the iron content was determined using an O.C plasma spectrometer. Plasma Spectrometer. Using the results of the analysis, the fractional yields 1 of the useful mineral content in the recovered mineral were calculated using the usual mass balance equations.

165 117

Table 1

Attempt Collector Overdosing kg / ton Alkanol- amine Overdosing kg / ton Fe recovery in waste Fe content in the recovered mineral 1® C ₉ H19O _(CH2) 3NH2 0.125 lack lack 0.940 0.573 2® 0.250 lack lack 0.883 0.611 3® C ₉ H ₁ 9O _(CH2) 3 NH ₂ 0.375 lack lack 0.798 0.634 4® C ₉ H19O (CH ₂ ) 3NH ₂ 0.500 lack lack 0.709 0.650 5 C ^^ OCCH ^ Ni ^ 0.250 OEA® 0.025 0.893 0.618 6 C9H ₁ 9O (CH2) 3 NH ₂ 0.250 OEA® 0.050 0.907 0.627 7 C ₉ H ₁₉ O (CH 2) ₁ NH ₂ 0.250 OEA ® 0.100 0.914 0.621 8 C9H ₁ 9O _(CH2) 3NH2 0.250 OEA ® 0.500 0.887 0.625 9 C9H 9O ₁ (CH _{2) j} NH ₂ 0.250 OEA ® 1,000 0.836 0.639 10 C9H ₁ 9O (CH2) 3NH2 0.125 OEA® 0.100 0.955 0.588 11 C9H19O (CH ₂ ) 3NH ₂ 0.375 OEA 2 0.100 0.834 0.640 12 89 ^ 90 (0 ^) 3 ^ 2 0.500 OEA © 0.100 0.769 0.658 13 C9H19O _(CH2) 3NH2 0.375 MEA 3) 0.100 0.816 0.639 14 C ₉ H1 ₉ O (CH ₂ ) 3 NH2 0.375 IPA ® 0.100 0.807 0.642 15 C ₉ H1 ₉ O (CH ₂ ) 3 NH2 0.375 TEA® 0.100 0.827 0.640 16 ® OETA condensate 6) 0.375 lack lack 0.823 0.617 17 OETA condensate 6) 0.375 OEA 0.100 0.843 0.619 18 OETA condensate 6) 0.375 MEA 0.100 0.840 0.623 19 OETA © condensate 0.375 IPA (4) 0.100 0.835 0.614 twenty OETA® condensate 0.375 TEA® 0.100 0.847 0.620 21 ® Tallow amine 0 ^ _ | θ 0.375 lack lack 0.744 0.657 22 The tallow amine 0.375 OEA ® 0.100 0.765 0.655 23 Tallow amine Cj. 6-18 0.375 MEA 3) 0.100 0.760 0.661 24 The tallow amine 0.375 IPA ® 0.100 0.756 0.659 25 Tallow amine 0 ^ _ ^ θ 0.375 TEA 5 0.100 0.764 0.658

165 117

continued table 1

Attempt Collector Dosage kg / ton Alkanol- amine Overdosing kg / ton Fe recovery in waste Fe content in the recovered mineral 26 ® c _1J h ₂₇ o (ch ₂ ) _j nh (ch ₂ ) _j nh ₂ 0, J75 lack lack 0.787 0.644 27 C ₁ J H ₂₇ O (CH ₂ ) _J NH (CH ₂ ) _J NH ₂ 0, J75 dea2) 0.100 0.809 0.650 28 C ₁ J H ₂₇ O (CH ₂ ) _J NH (CH ₂ ) _J NH ₂ 0, J75 MEA ® 0.100 0.801 0.654 29 C ₁ J H ₂₇ O (CH ₂ ) _J NH (CH ₂ ) _J NH ₂ 0, J75 ipa 4) 0.100 0.796 0.646 thirty C ₁ J H ₂₇ O (CH ₂ ) _J NH (CH ₂ ) _J NH ₂ 0, J75 tea © 0.100 0.807 0.651 Jl® C9H19O (CH2) jNH2 0, J75 DEA ® 0.100 0.814 0.642 ₃₂ ® C9H19O (CH2) jNH2 0, J75 OEA® 0.100 0.770 0.619 jj 1) C12H25NH2 0, J75 lack lack 0.7J8 0.65J J4 Ci2H25NH2 0, J75 0EA 2) 0.100 0.750 0.651 j ₅ D ^ jj ^ NH 0, J75 lack lack 0.744 0.648 J6 ^(C 6 ^H 1 ^{J )} 2 ^NH 0, J75 DEA 2) 0.100 0.751 0.652 j ₇ © M-210 9) 0, J75 lack lack 0.784 0.6J9 J8 M-210 9) 0, J75 DEA 2) 0.100 0.80J 0.644 J9 M-210 9) 0, J75 HO (CH2) 6NH2 0.100 0.788 0.648 40 M-210 (9) 0, J75 HO (CH2 ^ NH2 0.100 0.80J 0.6J1

(1 ©

(2 ©

© ©

(7) (8) (9)

Not according to the invention

Diethanolamine

Monoethanolamine

Isopropanolamine

Triethanolamine

Condensate of diethylenetetramine and tall oil fatty acid The slurry pH was adjusted to 5.5 using 1.0N HCl before the collector was added, the slurry pH was adjusted to 8.5 using 1.0N NaOH before the collector was added

Condensate of excess fatty acids and diethanolamine, commercially available from Oow Chemical Company.

The data presented in Table 1 show that the addition of alkanolamines in the reverse flotation process of the invention results in a greater recovery of iron in the waste than in a similar process carried out in the absence of alkanolamines. For example, comparing trial 2 with trials 5-8 shows that the addition of small amounts of alkanolamines results in increased iron recovery with increasing iron enrichment. That is, adding a small amount

The alkanolamine enhances the effectiveness of 3-nonyloxypropanamine as the collector used in these silica collection trials. Consideration of the other trials of the examples shows that different alkanolamines used with different amine collectors consistently result in enhanced separation of siliceous gangue from the desired iron in the process of the invention.

Example II: Reverse Flotation of Silica from Phosphate Ores. A series of 750 g samples of apatite containing phosphate ore from Florida was prepared. The raw material sampled had about 90% of the grains below 350 µm and 15% of the grains below 37 µm. It contained 26.8% SiO ₂ and 18.7% P2O5. The raw material to be treated was washed with a liquid containing sulfuric acid to clean the surface of the grains of organic matter present due to the previous treatment steps.

Each sample was transferred to the 3OOO ml chamber of an Agitair flotation machine equipped with an automated paddle removal system. Sufficient water was added to completely fill the chamber volume. The pH of the pulp was adjusted to 6.4 with 1.0 N NH 4 OH. Alkanolamine, if used, was added and the pulp was conditioned for 1 minute. The amine collector was then added and conditioned for an additional 1 minute. Methyl isobutyl carbinol was added as a frother in an amount of 5 g / tonne of dry ore.

The contents of the flotation cell were mixed at a speed of 900 revolutions per minute, introducing 9.0 liters per minute of air. Removal of the silica concentrate took place within 10 minutes. The phosphorus-containing waste and the concentrate containing silica gangue were dried, weighed and pulverized for analysis. Then it was dissolved in acid and the content of phosphorus (P2O5) was determined with the OC Plasma Spectrometer. Using the results of the analysis, the fractional yields and contents of the useful mineral, phosphorus (P ₂ Oj) in the recovered mineral were calculated using the usual mass balance equations and are presented in Table 2.

Table 2

Attempt Collector Overdosing kg / ton Alkanol- amine Overdosing kg / ton Yield P ^ in waste Content in the recovered mineral 1® The tallow amine 0.075 lack lack 0.901 0.242 2 (1) Tallow amine ^ 6_18 0.150 lack lack 0.869 0.264 3® The tallow amine 0.225 lack lack 0.824 0.294 4® Tallow amine C ^^ g 0.300 lack lack 0.773 0.329 5 Tallow amine Cj ^ -18 0.225 OEA © 0.025 0.837 0.294 6 Tallow amine C ^^ _ ^ g 0.225 OEA © 0.050 0.846 0.297 7 Tallow amine C ^^ g 0.225 OEA © 0.100 0.852 0.295 8 Tallow amine C ^^ g 0.225 MEA © 0.050 0.841 0.293 9 The tallow amine 0.225 IPA® 0.050 0.837 0.296 10 Tallow amine C ^ _18 0.225 TEA 5) 0.050 0.837 0.296 11® TETA © condensate 0.225 lack lack 0.857 0.272

165 117

continued table 2

Attempt Collector Dosage kg / ton Alkanol- amine Dosage kg / ton P2O5 yield in waste Content in the recovered mineral 12 TETA condensate 6) 0.225 DEA® 0.050 0.884 0.276 13 TETA® condensate 0.225 MEA® 0.050 0.877 0.275 14 TETA® condensate 0.225 IPA® 0.050 0.869 0.270 15 TETA condensate (6) 0.225 TEA® 0.050 0.879 0.280 16 (^ H ^ OCC ^^ Nt ^ 0.225 lack lack 0.870 0.257 17 C9H19O (CH ₂ ) ₁ NH ₂ 0.225 DEA® 0.050 0.889 0.255 18 C9H! 9O (CH2) 3NH2 0.225 MEA® 0.050 0.885 0.259 19 C9Hj, 9O (CH2) 3NH2 0.225 IPA ® 0.050 0.879 0.257 twenty C ₉ H19O (CH ₂ ) 1 NH ₂ 0.225 TEA® 0.050 0.886 0.254 21 TETA® condensate 0.225 - - 0.856 0.283 22 TETA® condensate 0.225 DEA® 0.050 0.879 0.287 23 TETA condensate 7) 0.225 MEA® 0.050 0.871 0.285 24 TETA® condensate 0.225 IPA® 0.050 0.869 0.282 25 TETA® condensate 0.225 TEA® 0.050 0.875 0.285 26® Tallow amine C ^. ^ G 0.225 - - 0.861 0.275 27 © Tallow amine C | ^ _ ^ g 0.225 DEA® 0.050 0.888 0.279 2Θ® Tallow amine C ^ - ^ 8 0.225 MEA® 0.050 0.880 0.273 29 (8) The tallow amine 0.225 IPA® 0.050 0.875 0.277 30® C 1-6 tallow amine 0.225 TEA® 0.050 0.890 0.277 31 Tallow amine C16-1S 0.225 HO (CH2) NH2 _fi 0.050 0.794 0.295 32 Tallow amine C ^ - ^ 0.225 HOCCH ^ NH ^ 0.050 0.823 0.290

© ©

© ©

© ©

© ©

Not according to the invention

Diethanolamine

Monoethanolamine

Isopropanolamine

Triethanolamine

Condensate of triethylenetetramine and fatty acid from tall oil. Acetate condensate of triethylenetetramine and fatty acid from tall oil. Collector added with 0.100 kg / tonne refined kerosene

165 117

The results presented in Table 2 demonstrate the effectiveness of the present invention in separating silica from phosphate ore. In either case, the addition of a small amount of alkanolamine increases the amine collector's ability to remove silica concentrate from phosphate waste with a higher yield, with comparable phosphorus enrichment.

Publishing Department of the UP RP. Circulation of 90 copies. Price PLN 10,000

Claims (5)

Patent claims A method of recovering minerals useful by reverse froth flotation by subjecting an ore containing silica or silica gangue in the form of an aqueous suspension to froth flotation, characterized in that the flotation is carried out in the presence of an amine collector and at least one alkanolamine under conditions where silica or siliceous gangue is flotated and useful minerals remain in the waste. 2. Method according to g a ^^^ zrz. 1, anamien ny tyra, the ore is iron ore oxide. 3. Method b according to claim k, y yyra replaced, ź a ore 1 ore and phosphate 4. Method according to z. I am sucking an alkali elcontleamine of (R) _xx ) where x is from I to 3 and each R is independently an alkanol of 1 to 6 carbon atoms. 5. The person according to claim k, zAmfieenny tyra that alkanolamine includes enalolatin, diedanolamine, thoitanolamine _and propanollamine, islpropanolatie, butanolamine, izlbudaeollatieę and mixtures thereof.